Pump devices for feeding pasty masses

Abstract

A pump device for feeding pasty masses includes a piston pump having a cylinder with a piston connected to a pre-fill container via an inlet. The inlet is delimited by an orifice plate closeable with a slide valve. The slide valve includes pivotable base body, a housing and a closure surface facing inside the housing. The closure surface is formed at least partially by a surface of a valve piston movable relative to the base body. The valve piston enters a hollow space formed in base body when a pressure from the pasty masses is applied to valve piston from inside the slide valve housing. The valve piston enters the hollow space compressing a fluid. A cutting ring constructed as an annular piston having a surface facing the hollow space is pressed in a closed position of the inlet slide valve against the orifice plate by pressure from the fluid.

What is claimed is: 
     
         1 . A pump device for feeding pasty masses, comprising:
 a piston pump having a cylinder with a piston connected with a pre-fill container via an inlet opening that is delimited by an orifice plate and can be closed with an inlet slide valve, the inlet slide valve comprising:   a pivotable base body, a slide valve housing and a closure surface facing an inside of the slide valve housing, said closure surface formed at least partially by a surface of a valve piston that is movable relative to the base body, wherein the valve piston can enter a closed hollow space formed in the base body when a pressure from the pasty masses is applied to the valve piston from the inside of the slide valve housing,   a fluid which is compressed when the valve piston enters the hollow space, and   a cutting ring constructed as an annular piston and having a surface facing the hollow space, said cutting ring being pressed in a closed position of the inlet slide valve against the orifice plate by pressure from the fluid.   
     
     
         2 . The pump device of  claim 1 , wherein the cutting ring is constructed with a U-shaped annular cross-section, and wherein the cutting ring is slidingly sealed with an outer inside diameter against the base body and with an inner inside diameter against the valve piston. 
     
     
         3 . The pump device of  claim 1 , wherein the valve piston has on a side facing the fluid a substantially cylindrical shaft which is slidingly supported in a cylindrical bore of the base body and which, in conjunction with an envelope of the piston, forms a guide that secures the valve piston against canting. 
     
     
         4 . The pump device of  claim 3 , wherein the shaft of the valve piston sealingly extends through the base body and is axially movable therein. 
     
     
         5 . The pump device of  claim 1 , wherein the inlet slide valve comprises a pre-biased spring element which operates on the valve piston in an identical direction as the pressure from the pasty masses. 
     
     
         6 . The pump device of  claim 5 , wherein the spring element is formed by one or more disc springs. 
     
     
         7 . The pump device of  claim 5 , wherein the spring element is tensioned by introducing the fluid into the hollow space, thereby moving the valve piston against an effective direction of the pressure from the pasty masses and securing the hollow space with the fluid against fluid leakage by a check valve or a stopper. 
     
     
         8 . The pump device of  claim 5 , wherein the spring element is supported on the cutting ring. 
     
     
         9 . The pump device of  claim 1 , wherein the inlet slide valve is a pivoting flat slide valve having a pivot shaft. 
     
     
         10 . The pump device of  claim 9 , wherein the base body is partially guided in a guide groove, wherein the pressure from the pasty masses residing inside the cylinder applies a hydrostatic force on the closed pivoting flat slide valve, and wherein the hydrostatic force is partially taken up by a pulling force of the pivot shaft supporting the inlet slide valve and partially by a force with which the base body is supported in the guide groove. 
     
     
         11 . The pump device of  claim 9 , wherein a connection of the base body with the pivot shaft allows a small pendulum motion about an axis extending essentially horizontally and perpendicular to a pivot axis.